Battle of Yangping Gate (249)

The Battle of Yangping Pass was a classic Chinese battle fought in 249 AD, where a retreating Shu Han army under Jiang Wei, protege of the late Zhuge Liang, halted a Cao Wei pursuit by using an Arbalest contraption devised by Zhuge in 234 AD.

Background
Jiang Wei was forced to retreat after the Battle of Mt. Niutou on his Second Northern Expedition, and made it to Yangping Gate, where Sima Shi and a Cao Wei army from Luoyang engaged his retreating troops. The Wei troops were repelled by Shu Han's arbalests, which were boards that fired ten large arrows at a time in one volley, a sort of Hwacha.